The No. 1-ranked Djokovic is coming off a 70-6 season in which he won three Grand Slam titles. The 24-year-old Serb ended his best ever season with two tired losses at the ATP World Tour Finals last month but got back to winning ways against the No. 16-ranked Monfils.
Djokovic will face Roger Federer in the semifinals on Friday when Rafael Nadal will meet fellow Spaniard David Ferrer.
Ferrer earlier beat Jo Wilfried Tsonga of France 2-6, 7-6 (5), 6-2 in the $250,000 winner-takes-all six-man championship.
The new ATP season begins next week ahead of the Australian Open from Jan. 16-29.
Meanwhile, Rafael Nadal says he plans to take several weeks off after the Australian Open to recover from a nagging shoulder injury.
The second-ranked Nadal said the injury surfaced during the ATP World Tour Finals in London and that he was still "not 100 percent." He said he made a decision three days ago to defend his title at in Abu Dhabi.
